The present invention generally relates to an automated packaging machine for forming a wrap-around product carton. More specifically, the present invention relates to a high speed rotary blank feeder and rotary board erector that combine to sequentially remove a planar carton blank from a stack of carton blanks and partially fold the carton blank into the product carton such that the product carton can be loaded with articles.
Currently, automated packaging machines exist that automatically remove planar carton blanks from a stack and fold the pre-scored carton blanks into a product carton that can then be loaded with articles, such as a twelve-pack or twenty-four-pack of beverage containers. After the desired number of articles have been loaded into the partially folded product carton, additional downstream processing closes and seals the product carton for shipment. Although currently available automated packaging machines are capable of folding and loading a product carton as described, limitations exist as to the speed at which the product cartons can be formed and filled with a set of individual articles.
A significant limitation on the speed at which a product carton can be formed and filled is the rate at which individual carton blanks can be unstacked and partially folded into a state such that the carton can receive a set of individual articles. Specifically, a major limitation in currently available automated packaging machines is the rate at which individual carton blanks can be fed from a stack.
Currently, the most common method of removing planar carton blanks from the bottom of a hopper is to utilize a reciprocating vacuum head that travels upward into contact with the lowermost carton blank. When the vacuum head is in contact with the lowermost carton blank, a source of negative pressure attracts the carton blank to the vacuum cups on the vacuum head. Once the carton blank is in contact with the vacuum head, the vacuum head is retracted, which pulls the lowermost carton blank from the stack onto a conveyor assembly. Once the carton blank is on the conveyor assembly, the source of negative pressure is removed and the vacuum head reciprocates back up into contact with the lowermost carton blank.
As can be understood by the above description, the speed at which individual carton blanks can be fed from the hopper is limited by the reciprocating motion of the vacuum head. In addition to the reciprocating vacuum heads, the speed of current wrap-around multipackers is limited by the rate at which the planar carton blanks can be folded into a preliminary state that can receive the articles being packaged.
Therefore, a need exists for an automated wrap-around multipacker that includes a high speed blank feeder to feed planar carton blanks into the rest of the system. Further, a need exists for a board erector that can receive carton blanks from the blank feeder and fold the carton blanks into a partially folded product carton for loading with articles.
The present invention includes a novel carton blank feeding section and carton folding section for an automated high speed wrap-around multipacker. The blank feeding and carton folding sections of the present invention allow the wrap-around multipacker to increase its operational speed to significantly increase the number of articles that can be packaged by the entire system.
The carton blank feeding section includes a rotary blank feeder that is positioned beneath an overhead hopper containing a stack of planar carton blanks. The rotary blank feeder includes a plurality of feeder arms that are rotatable about a common axis of rotation. The plurality of feeder arms form an integral feeder arm assembly that is both rotatable about the common axis of rotation and rotatable about a second axis of rotation spaced from the common axis of rotation. The rotary movement of the feeder arm assembly about two axes of rotation allows the vacuum head formed on each of the feeder arms to move along an astroid-shaped path. The astroid-shaped path of movement of each vacuum head allows the rotary board feeder to pull the lowermost carton blank from the accumulated stack and move the carton blank vertically and laterally onto a board feed conveyor assembly.
Each of the vacuum heads formed on the feeder arms of the feeder arm assembly is independently rotatable relative to the feeder arm itself. A series of gears and internal belts allows the vacuum head to maintain a constant horizontal orientation such that the vacuum head can grasp and transfer the carton blank from the overhead hopper. The feeder arm assembly is operable such that each vacuum head moves upward into contact with the lowermost carton blank and applies a source of negative pressure to the lowermost carton blank to remove the carton blank from the accumulated stack. The inclusion of three separate feeder arms within the feeder arm assembly allows the rotary blank feeder to increase the rate at which carton blanks are removed from the accumulated stack.
After each planar carton blank has been removed from the overhead hopper, the planar carton blank is grasped by one of the folding arms of a rotary board erector. The rotary board erector includes a plurality of folding arms that each rotate about a common axis of rotation. The folding arms each include a folding head having a pair of grasping vacuum cups that contact the planar carton blank and hold the planar carton blank in contact with the folding head.
Each folding arm includes a cam slot that receives a drive pin used to rotate the folding arm about a common axis of rotation. Movement of the drive pin within the cam slot decreases the rotational speed of each folding arm as the folding arm rotates from an upright, grasping position to a bottom dead center unloading position. The decrease in rotational speed of each folding arm allows the rotary board erector to compensate for the differences in linear speed between the movement of the planar carton blank on the board feed conveyor and the linear movement of the carton blank once it has been partially folded by the rotary board erector.
Each folding head of the rotary board erector includes a grasping suction cup that attracts a portion of the carton blank as the carton blank is folded by a folding assembly positioned adjacent to the rotary board erector. The folding assembly includes a plurality of folding bars that contact and fold the carton blank about pre-scored lines on the carton blank. Once the carton blank has been folded, the carton blank is held in its folded position by the folding vacuum cup.
The rotary board erector positions each of the partially folded carton blanks within a pocket formed between lugs on a pair of pocket chains. The product chains transfer the partially folded carton blank to a downstream location where articles can be inserted into the partially folded carton blank.
As can be understood by the above description, the rotary blank feeder and rotary board erector of the present invention allow for an increase in the operational speed of the multipacker incorporating these components. The increase in operational speed of the multipacker results in an increase in operating efficiency and product output.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.